How do rails move through thick marsh vegetation without being noticed?

Rails are able to move through thick marsh vegetation without being noticed primarily due to their slender body shape, which facilitates easy movement through reeds and marsh grasses.1

These birds are inherently secretive, typically hiding among reeds at the water’s edge during the day. Their plumage, which consists mostly of dull grays and browns often marked with irregular patterns, provides effective camouflage within their dense habitat. While they are capable of flight, they are reluctant to take wing when disturbed; instead, they prefer to drop to the ground and rely on their ability to run through vegetation to remain hidden.1